This invention relates generally to a projectile for the insertion of filling yarns in a loom, wherein the filling yarn is supplied from supply packages located outside of the loom. The invention is particularly directed to a projectile of the type in which at least a portion of the filing yarn is stored in a filling storage chamber within the projectile. This type of projectile and the loom with which it is used, is shown in U.S. Pat. No. 3,831,640 to Karl W. Wueger, dated Aug. 27, 1974. The projectile disclosed in that U.S. patent is designed for firing alternately from opposite sides of the loom. Because of this, the projectile is provided with a filling storage chamber at each end thereof and means are provided to allow air to pass from one end of the projectile to the other. This flow of air is instrumental in depositing the filling yarn in the storage chamber prior to propulsion of the projectile through the warp shed of the loom for a filling insertion.
The invention is particularly directed to the class of projectiles in which at least a portion of a filling pick is inserted by use of air. Accordingly, the projectiles are designed to permit air to flow through the storage chamber from an inlet opening to allow the filling yarn entering the inlet opening to be carried by this air flow and be deposited within the chamber. The position of the filling in the storage chamber represents no particular problem, but the manner in which the filling is deposited is critical for the withdrawal of the filling as the projectile passes through the warp shed. If the filling is deposited in a random manner, snarls are likely to occur as the filling is withdrawn. In addition, it is important that the filling be withdrawn smoothly and evenly. Another problem sometimes encountered is that the means which permits air to flow through the chamber for depositing filling within the chamber also causes a reverse air flow during the projectile flight, thus causing the filling yarn stored in the chamber to be blown out of the trailing end of the projectile prematurely and thereby to deposit the filling in a bunch or snarl within the warp shed. This produces a defective pick and defective cloth. Occasionally, difficulties have also been encountered in loading the filling into the projectile. As the filling is deposited in the storage chamber, it tends to settle against the outlet openings of the chamber and to block these openings. This reduces air flow through the projectile and interferes with the proper deposit of additional filling yarn.
Many of the above problems have been overcome by the projectile design of my prior U.S. Pat. No. 4,095,620 issued jointly with Victor F. Sepavich on June 20, 1978 and entitled "PROJECTILE FOR WEFT INSERTION". The projectile in this patent provides an air passageway which connects the storage chamber to the outlet opening of the projectile. The air communication between the chamber and passageway extends along the entire length of the passageway so that, as the yarn is deposited within the chamber, a portion of this connection is blocked, but there always remains some communication between the chamber and passageway. In addition, the communication between the storage chamber and passageway is lateral to the traveling axis of the projectile, so that there is no direct effect on the filling within the chamber from the air entering the projectile through the leading end of the projectile. However, one of the problems encountered with the projectile of my U.S. patent, supra, and the Wueger patent, supra, is in the withdrawal of filling from the projectile during its flight through the warp shed. Due to the cylindrical design of the storage filling chamber, the filling is deposited within the chamber in circular loops. Ocasionally, air turbulence interferes with the proper disposition of the loops. Because of this, there is a tendency for subsequently-formed loops to form within previously-formed loops. This may result in snarling or tangling as the filling is withdrawn. In this regard, it is highly desirable that the filling be deposited within the chamber progressively from the inner extremity of the chamber toward the inlet opening, so that as each length of filling is withdrawn, it does not interfere with filling deposited previously.
It is a principle object of the present invention to provide a loom projectile which includes a filling storage chamber in which filling is deposited in a manner which permits the filling to be withdrawn evenly and smoothly from the projectile without causing snarls or twists.
Another object of the invention is the provision of a loom projectile in which the stored filling cannot be blown out of the filling storage chamber prematurely during its flight through the warp shed.
A further object of the present invention is the provision of a loom projectile having a filling storage chamber in which the filling yarn is deposited within the chamber in uniform lengths progressively from the interior of the chamber toward the inlet opening to permit smooth and even withdrawal of the filling.